1. Field of the Invention
This invention relates to footwear, in particular sports footwear.
2. Discussion of the Background
The characteristics of sports footwear vary considerably. In particular, over the years it has been sought to design sports footwear or shoes which restore to the user part of the energy which he directs towards the ground or resting surface during walking, running, jumping or other movements. A large number of designs tending to achieve this object are therefore known. They generally comprising elastic inserts arranged within the sole unit preferably at the heel. Although these known designs achieve satisfactory results, they have various drawbacks. These include: excessive footwear weight leading to obvious problems of premature tiredness for the user (for example an athlete) during use; considerable constructional complexity leading to imperfect mounting of the sole unit and/or of the insert positioned in it with consequent imperfect energy return to the user's foot; a non-anatomical shape of the sole unit or insole positioned in contact with it, hence penalizing the user during use. To this can be added the fact that a rubber sole absorbs moisture during use and, in particular, retains soil on muddy ground, leading to a further footwear weight increase with obvious consequences for the user.